GENTLE & MESMERIZING, the famous Gounod Ave Maria is based on the opening piece to Bach's Well-Tempered Clavier, a book of 24 preludes and fugues. The Prelude in C Major, the most famous as well as the simplest of the preludes, consists of a sequence of arpeggiated chords travelling through different keys and moods. Gounod added a bar to Bach's progressions and superimposed a graceful melody on it using the Latin text of the Ave Maria, aka the Hail Mary.